Concrete floor and ceiling system without steel reinforcing

ABSTRACT

A building component system including a rigid plastic form having an arched shape in each of two perpendicular vertical planes and having a plurality of protrusions configured to engage concrete poured on top of the rigid plastic form. The system also includes concrete poured on top of the form and cured to bind to the form at least at the plurality of protrusions, thereby forming an arched ceiling for a first story of a building and a flat roof or flat floor for a second story of a building.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of Provisional Application. No.62/340,042, filed May 23, 2016, the entire contents of which are herebyincorporated by reference as if fully set forth herein, under 35 U.S.C.§119(e).

BACKGROUND

Concrete construction has brought many advantages to the constructionindustry since being reintroduced to the world in the late 19^(th)century. Poured concrete was used in ancient Rome, famously for the domeof the Pantheon, but the recipe was lost for millennia. Concrete(composed of Portland Cement, sand, aggregate and water) offers manyadvantages to other types of framing, including, among others, that: 1)it is composed of basic and easily transported materials; 2) it ismalleable when first mixed so it can assume many shapes; 3) it has greatcompressive strength; and, 4) it is resistant to fire.

However, concrete is poor in its tensile strength. For this reason, itis paired with steel often in the form of re-bar (reinforcing bars)and/or wire mesh. Such pairing is labor intensive regarding transportand placement. Concrete also requires a labor intensive complex formworkto be placed so that the final structure can assume an irregular shape;and, after the concrete is set, the forms must be removed. While modernreusable form systems have reduced the cost of material, the labor costsremain high.

SUMMARY OF THE INVENTION

Techniques are provided for a consumable formwork that is incorporatedinto the final structure and provides sufficient tensile strength thatsteel reinforcing can be omitted.

In a first set of embodiments, a building component system includes arigid plastic form having an arched shape in each of two perpendicularvertical planes and having a plurality of protrusions configured toengage concrete poured on top of the rigid plastic form. The system alsoincludes concrete poured on top of the form and cured to bind to theform at least at the plurality of protrusions, thereby forming an archedceiling for a first story of a building and a flat roof or flat floorfor a second story of a building.

In some embodiments of the first set, when the form is placed on a flatsurface, a space below the form is sufficient for use as a residence forhumans or animals or equipment or some combination.

In some embodiments of the first set, the concrete is not reinforcedwith steel.

In some embodiments of the first set, the system includes two or moretemporary vertical forms disposed outside the rigid plastic form forproviding an outer perimeter of the building component, wherein thetemporary vertical forms are removed after the concrete is poured andcured.

In some embodiments of the first set, a plurality of the rigid plasticforms stack efficiently for transportation of the plurality of rigidplastic forms.

In some embodiments of the first set, the system includes a moldconfigured to fabricate the rigid plastic form by injection molding.

In a second set of embodiments, a method includes placing a rigidplastic form having an arched shape in each of two perpendicularvertical planes and having a plurality of protrusions configured toengage concrete poured on top of the rigid plastic form, and placing twoor more simple vertical forms outside the rigid plastic form forproviding an outer perimeter of a building component. The methodincludes pouring and curing concrete on top of the form to bind to theform at least at the plurality of protrusions. The method also includesafter the concrete cures, removing the two or more simple verticalforms, thereby forming an arched ceiling for a first story of a buildingand a flat roof or flat floor for a second story of a building.

Still other aspects, features, and advantages are readily apparent fromthe following detailed description, simply by illustrating a number ofparticular embodiments and implementations, including the best modecontemplated for carrying out the invention. Other embodiments are alsocapable of other and different features and advantages, and its severaldetails can be modified in various obvious respects, all withoutdeparting from the spirit and scope of the invention. Accordingly, thedrawings and description are to be regarded as illustrative in nature,and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated by way of example, and not by way oflimitation, in the figures of the accompanying drawings in which likereference numerals refer to similar elements and in which:

FIG. 1A and FIG. 1B are block diagrams that illustrate examplecompression and tensile forces on a concrete slab that are to bemodified according to an embodiment;

FIG. 2A and FIG. 2B are block diagrams that illustrate an exampleconsumable form that mitigates the need for steel reinforcing, accordingto an embodiment;

FIG. 3A and FIG. 3B are block diagrams that illustrate example use ofmultiple consumable forms that mitigates the need for steel reinforcingto frame a structure, according to an embodiment;

FIG. 4A and FIG. 4B are block diagrams that illustrate an examplestructure resulting from use of multiple consumable forms that mitigatesthe need for steel reinforcing, according to an embodiment;

FIG. 4C and FIG. 4D are block diagrams that illustrate an examplestructure resulting from use of multiple consumable forms and pillars,according to an embodiment;

FIG. 5A and FIG. 5B are block diagrams that illustrate example stackingof multiple consumable forms that mitigates the need for steelreinforcing, according to an embodiment;

FIG. 6A and FIG. 6C and FIG. 6H and FIG. 6I are perspective drawingsthat depict an example plastic form for forming a chamber ofintersecting arches from above, from the side, from the front, andobliquely, respectively, according to an embodiment;

FIG. 6B is perspective drawing that depicts an inside half view of thesame example plastic, according to an embodiment;

FIG. 6D through FIG. 6G are cross sectional drawings that depict thesame example plastic form at different longitudinal positions, accordingto an embodiment;

FIG. 7 is perspective drawing that depicts pouring cement onto multipleforms of the type depicted in FIG. 6A through FIG. 6I, according to anembodiment;

FIG. 8A is a photograph that depicts an example set of four plasticforms scaled down to a length of about one foot and a width of about 3inches, according to an embodiment;

FIG. 8B is a photograph that depicts the example set of four plasticforms from FIG. 8A, set adjacent to each other for framing a concretestructure of one square foot, according to an embodiment;

FIG. 8C is a photograph that depicts the example set of four plasticforms from FIG. 8A stacked for transport, according to an embodiment;

FIG. 9A is a photograph that depicts the example set of four plasticforms from FIG. 8A, set adjacent to each other for framing a concretestructure on a wall of plywood planks, according to an embodiment;

FIG. 9B is a photograph that depicts the example set of four plasticforms from FIG. 8A, set adjacent to each other for framing a concretestructure on a wall of plywood planks with simple side framing,according to an embodiment;

FIG. 9C is a photograph that depicts the example framing of FIG. 9Bafter pouring concrete, according to an embodiment;

FIG. 9D is a photograph that depicts an example structure incorporatingthe example plastic forms of FIG. 9A, according to an embodiment;

FIG. 10A is a photograph that depicts the example structure of FIG. 9Dexternally loaded with a bending stress of 10 pounds, according to anembodiment;

FIG. 10B is a photograph that depicts the example structure of FIG. 9Dexternally loaded with a bending stress of 20 pounds and then maintainedfor 7 weeks, according to an embodiment;

FIG. 10C is a photograph that depicts the example structure of FIG. 9Dexternally loaded with a bending stress of 50 pounds through 15 weeksafter adding another 10 pounds for a total of 60 pounds, according to anembodiment;

FIG. 10D is a photograph that depicts the example structure of FIG. 9Dexternally loaded with a bending stress of 60 pounds through 16 weeksafter adding another 10 pounds for a total of 70 pounds, according to anembodiment;

FIG. 10E is a photograph that depicts the example structure of FIG. 9Dexternally loaded with a bending stress of 70 pounds through 17 weeksafter adding another 11 pounds (an 8 pound barbell and a 3 pound disk)for a total of 81 pounds, according to an embodiment; and

FIG. 10F is a photograph that depicts a side view of the examplestructure of FIG. 9D with 81 pounds per square foot at 17 weeks,according to an embodiment.

DETAILED DESCRIPTION

A method and apparatus are described for consumable formwork forconcrete structures without steel reinforcing. In the followingdescription, for the purposes of explanation, numerous specific detailsare set forth in order to provide a thorough understanding of thepresent invention. It will be apparent, however, to one skilled in theart that the present invention may be practiced without these specificdetails. In other instances, well-known structures and devices are shownin block diagram form in order to avoid unnecessarily obscuring thepresent invention.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope are approximations, the numerical values set forth inspecific non-limiting examples are reported as precisely as possible.Any numerical value, however, inherently contains certain errorsnecessarily resulting from the standard deviation found in theirrespective testing measurements at the time of this writing.Furthermore, unless otherwise clear from the context, a numerical valuepresented herein has an implied precision given by the least significantdigit. Thus a value 1.1 implies a value from 1.05 to 1.15. The term“about” is used to indicate a broader range centered on the given value,and unless otherwise clear from the context implies a broader rangearound the least significant digit, such as “about 1.1” implies a rangefrom 1.0 to 1.2. If the least significant digit is unclear, then theterm “about” implies a factor of two, e.g., “about X” implies a value inthe range from 0.5X to 2X, for example, about 100 implies a value in arange from 50 to 200. Moreover, all ranges disclosed herein are to beunderstood to encompass any and all sub-ranges subsumed therein. Forexample, a range of “less than 10” can include any and all sub-rangesbetween (and including) the minimum value of zero and the maximum valueof 10, that is, any and all sub-ranges having a minimum value of equalto or greater than zero and a maximum value of equal to or less than 10,e.g., 1 to 4.

Some embodiments of the invention are described below in the context ofa particular shape for stackable forms. However, the invention is notlimited to this context. In other embodiments the forms do not stack butare fabricated in place using one or more molds and a supply of asuitable plastic material with an injection molding process, or using a3D printer and a supply of a suitable plastic material.

As used herein the term “plastic,” when used as a noun, refers to amaterial consisting of any of a wide range of synthetic orsemi-synthetic organic compounds that are malleable and can be moldedinto solid objects. Plastics are typically organic polymers of highmolecular mass, but they often contain other substances. They areusually synthetic, most commonly derived from petrochemicals, but manyare made from renewable materials such as polylactic acid from corn orcellulosics from cotton linters. Plasticity is the general property ofall materials that are able to irreversibly deform without breaking, butthis occurs to such a degree with this class of moldable polymers thattheir name is an emphasis on this ability. Due to their relatively lowcost, ease of manufacture, versatility, and imperviousness to water,plastics are used in an enormous and expanding range of products.

Overview of Forms

FIG. 1A and FIG. 1B are block diagrams that illustrate examplecompression and tensile forces on a concrete slab that are to bemodified according to an embodiment of the present invention.Compression forces act to compress a material by pushing moleculestogether, while tensile forces act to pull molecules apart by pulling ona material in opposite directions causing the material to stretch. Theforce is usually expressed as a stress, which is a force per unit area.Both compressive stress and tensile stress come to bear when a bendingforce or stress is applied to a structure, as indicated in FIG. 1A andFIG. 1B. FIG. 1A depicts a plate 110 a suspended on two pillars 120subjected to a bending force, called load 190, caused by the weight ofthe plate 110 a or some additional objects placed on the plate 110 a, orsome combination. In response, as depicted in FIG. 1B, the plate 110 btends to bend into a configuration in which the material close to thebending force is subject to a compressive stress 192 and the materialopposite the bending force is subject to a tensile stress 194.

As stated above concrete is a common building material. While concreteis resistant to failure due to compressive stress 192, it is subject tofailure due to tensile stress 194. Tensile strength is a measure of theability of a material to withstand a tensile stress, expressed as thegreatest tensile stress that the material can stand without breaking.For this reason a concrete plate is constructed with steel bars, calledreinforcement bars (or “rebar”), because steel has a higher tensilestrength than concrete. However, steel is expensive and heavy to move.As a consequence, steel rebar is not readily available in manydisadvantaged areas where housing and other buildings are needed.

Plastic is a lighter and less expensive material than steel, and thusplastic is more readily available in disadvantaged areas than steel. Inaddition, plastic has superior tensile strength compared to concrete.Furthermore, the malleable properties of plastic also are advantageousfor generating forms of arbitrary shape. Thus, it is advantageous to useplastic for both purposes simultaneously, e.g., to provide forms forshaping concrete and to stay in place to provide tensile strength forthe resulting concrete structure. To provide tensile strength for theresulting structure, features are added to the plastic forms to engagethe concrete; and, thus, work with the concrete to resist various loadsthat impart a tensile stress. Furthermore, plastic is superior tofiberglass suggested in the prior art, because the tensile strength ofplastic is much greater (about 16 times greater) than the tensilestrength of fiberglass that has a tensile strength only slightly greater(less than a factor of two greater) than concrete. Table 1 summarizestensile strength and other properties of these materials.

TABLE 1 Properties of various materials. MODULUS COMPRESSIVE TENISLE OFMATE- STRENGTH STRENGTH ELASTICITY DENSITY RIAL psi psi psi pcf Concrete4,000 500 3,600,000 150 Steel 36,000 70,000 29,000,000 483 Fiberglass135 805 1,200,000 112 (70% Egb) Plastic 12,000 13,000 1,800,000 83(nylon 6)

In some embodiments, the plastic forms are shaped to provide sufficientheight and width for the resulting structure that the resultingstructure can be used as a supported ceiling for a first story and afloor for the story above. Thus modular buildings can be rapidlyconstructed with one or a few different plastic forms and concretewithout steel reinforcing, e.g., without steel rebar. In manyembodiments, the formwork's geometry uses parabolas and arches to pushthe concrete to almost pure compression, especially as the bending loadmoves from the center toward the edges. In some embodiments, the formsare also shaped to efficiently stack, which is an advantage in thetransport of multiple such forms. In some embodiments, the forms arefabricated on site, and the forms need not be designed to stackefficiently.

Thus the embodiments described herein is distinguished over thefiberglass forms described in prior U.S. Pat. No. 8,991,137 by usingplastic of greater tensile strength or providing greater vertical extentof the arches so that the concrete is working more in compression andless reliant on the tensile strength of the form, or both. In someembodiments, the vertical extent is sufficient that the space below theform is suitable for housing humans or animals or equipment without theuse of additional walls or pillars.

FIG. 2A and FIG. 2B are block diagrams that illustrate an exampleconsumable form 210 that mitigates the need for steel reinforcing,according to an embodiment of the present invention. This exampleembodiment also stacks sufficiently well to allow many such forms to betransported together on a flatbed truck or rail car or cargo hold ofship or aircraft or other vehicle. In this illustration, Z refers to thevertical direction, while X and Y refer to perpendicular horizontaldirections. In the illustrated embodiment, the form has a curved plate212 that is arched over a long distance in the X-Z plane and arched overa shorter distance in the perpendicular Y-Z plane. In addition, theframework has an articulated surface with protuberances 214, such asflanges, which increase surface friction and allow the concrete to grab,and transfer tensile stresses to, and otherwise interact with the form210. In some embodiments, at different cross sections, the form does notreach the ground so as to provide opening between chambers generated bythe form, as shown in more detail for the example embodiment withreference to FIG. 6A and following. The cross sections depicted wereselected to show that the form reaches the ground to form at least fourlegs to support the form and the resulting structure. In someembodiments, only three legs are used; and, in other embodiments, morethan four legs are formed. In some embodiments, the form 210 alsoincludes components 216 and 218 that serve as spacers to control theseparation between adjacent forms when placed at a construction site inthe X and Y directions, respectively.

Overview of Method of Use

FIG. 3A and FIG. 3B are block diagrams that illustrate example use ofmultiple consumable forms that mitigates the need for steel reinforcingto frame a structure, according to an embodiment. As depicted, a singleform 210 is placed in the X direction between two simple vertical forms320 in the Y-Z plane. In other embodiments, more forms are placed in theX-direction. Multiple forms 210 a, 210 b, 210 c, 210 d and 210 e areplaced in the Y direction between two simple vertical forms 330 in theX-Z plane. In other embodiments, fewer or more forms are placed in the Ydirection. In some embodiments, the spacing between adjacent forms isvaried or subject to the discretion of the builder. In some embodiments,the forms are spaced at least a distance apart determined by any spacers216, 218 present on the forms. The forms are then filled with concreteto a level above the highest portion of the forms and protuberances 214.In some embodiments, the forms 210 a through 210 e are each shored upwith one or more supports until the concrete cures into a solid form.

FIG. 4A and FIG. 4B are block diagrams that illustrate an examplestructure resulting from use of multiple consumable forms that mitigatesthe need for steel reinforcing, according to an embodiment. In the X-Zplane the structure forms a chamber that has an arched ceiling that ishigh enough to serve its purpose, e.g., greater than or equal to theheight of the persons or animals or equipment or provisions to be housedin the structure. In the Y-Z plane the structure has multiple archedentrances to the interior chamber or chambers. The top of the structureprovides a flat floor 410 for the next story. Where both the X-Z formand the Y-Z form touch the ground, a leg is formed that stands on theground and supports the vaulted ceiling 420 and flat floor 410 with purecompressive stress well supported by the concrete. A second story canthen be formed by repeating the process depicted in FIG. 3A and FIG. 3Bon top of the structure depicted in FIG. 4A and FIG. 4B.

FIG. 4C and FIG. 4D are block diagrams that illustrate an examplestructure resulting from use of multiple consumable forms and pillars430, according to an embodiment. In this embodiment, pillars are formedusing conventional or simple forms, or preformed pillars are erected andthe forms are placed on top of the pillars. FIG. 4C shows therelationship of legs to pillars in the Y-Z plane; (the pillars are shownin black and occur only at the ends of the form) and, FIG. 4C shows therelationship of legs to pillars in the X-Z plane. After concrete ispoured and cured, the structure sits atop pillars; one pillar supportingeach leg.

FIG. 5A and FIG. 5B are block diagrams that illustrate example stackingof multiple consumable forms 210 a-d that mitigates the need for steelreinforcing, according to an embodiment. Such stacking is advantageousfor the transport of multiple forms to a building site on truck, train,boat or aircraft.

Experimental Embodiment

According to an example experimental embodiment, a scale model wasconstructed to test the strength of the resulting structure. It isdesirable in building application that a floor be able to withstand abending load of 30 pounds per square foot (psf, 1 psf=47.8803 newtonsper square meter) for the life of the building for most residential andlight commercial applications. The experimental embodiment presentedhere demonstrates that this embodiment would allow for quick and lessexpensive means to build flat floors and/or roofs that are capable ofholding 30 pounds per square foot of live load or more.

To test the ideas, we had 1/24 scale models of the form made in plastic(nylon 6) on a 3D printer. A structure was assembled as it would be inthe field by pouring concrete on the form. This gave a platform of 8″×6″which is one third of a square foot (48 square inches is one third of144 square inches equal to one square foot). Considering what ishappening on the molecular level, the 1/24 scale would seem aninsignificant magnitude difference—particularly since both the model andthe full scale version would ultimate act monolithically. After 28 daysof curing time the structure was loaded with 10 pounds 7 ounces which isthe equivalent of over 31 psf. After a week, the load has held withoutcracking or failure. After carrying the load for 4 weeks, the load wasincreased repeatedly until failure.

FIG. 6A and FIG. 6C and FIG. 6H and FIG. 6I are perspective drawingsthat depict an example plastic form 610 for forming a chamber ofintersecting arches from above, from the side, from the front, andobliquely, respectively, according to an embodiment. FIG. 6B isperspective drawing that depicts an inside half view of the same exampleplastic, according to an embodiment. This design for the form providesfor substantial intrusions of concrete between horizontally displacedportions of the frame to more fully engage the tensile strength of theform with the tensile stresses on the structure.

FIG. 6D through FIG. 6G are cross sectional drawings that depict thesame example plastic form at different longitudinal positions, accordingto an embodiment. At different longitudinal positions, the form descendless far from the top and includes a shelf that holds cement above theform and covers the distance to the next adjacent form. FIG. 6D shows asolid section 630 that represents the dips in the form that allow thesubstantial intrusion of concrete below the top profile of the form.FIG. 6E shows a flange with holes 640 to engage the concrete and helptransfer tensile stresses from the concrete to the form. FIG. 6D through6I also show curved arch plates 612, protuberances 614 and spacercomponents 616, 618 from different perspectives.

FIG. 7 is a perspective drawing that depicts pouring cement 700 ontomultiple forms 710 of the type depicted in FIG. 6A through FIG. 6I,according to an embodiment. The forms are set above walls 720 to form avaulted ceiling for a rectangular room and a floor for the story above.

FIG. 8A is a photograph that depicts an example set of four plasticforms scaled down to a length of about one foot and a width of about 3inches, according to an embodiment. FIG. 8B is a photograph that depictsthe example set of four plastic forms from FIG. 8A, set adjacent to eachother for framing a concrete structure of one square foot, according toan embodiment. FIG. 8C is a photograph that depicts the example set offour plastic forms from FIG. 8A stacked for transport, according to anembodiment.

FIG. 9A is a photograph that depicts the example set of four plasticforms from FIG. 8A, set adjacent to each other for framing a concretestructure on a wall of plywood planks, according to an embodiment. FIG.9B is a photograph that depicts the example set of four plastic formsfrom FIG. 8A, set adjacent to each other for framing a concretestructure on a wall of plywood planks with simple side framing,according to an embodiment. FIG. 9C is a photograph that depicts theexample framing of FIG. 9B after pouring concrete, according to anembodiment. FIG. 9D is a photograph that depicts an example structureincorporating the example plastic forms of FIG. 9A, according to anembodiment. This structure provides a vaulted ceiling for the roombetween the two plywood planks and a floor for a story above.

FIG. 10A is a photograph that depicts the example structure of FIG. 9Dexternally loaded with a bending stress of 10 pounds plus 7 ounces of atwo by four, according to an embodiment. FIG. 10B is a photograph thatdepicts the example structure of FIG. 9D externally loaded with abending stress of 20 pounds and then maintained for 7 weeks, accordingto an embodiment. No failure by the structure is indicated, suggestingthat the tensile strength provided by the plastic frame suffices for asustained external load of 3×20=60 pounds per square foot.

FIG. 10C is a photograph that depicts the example structure of FIG. 9Dexternally loaded with a bending stress of 50 pounds through 15 weeksafter adding another 10 pounds for a total of 60 pounds, according to anembodiment. No failure by the structure is indicated, suggesting thatthe tensile strength provided by the plastic frame suffices for asustained external load of at least 50×3=150 pounds per square foot anda temporary load of 3×60=180 pounds per square foot.

FIG. 10D is a photograph that depicts the example structure of FIG. 9Dexternally loaded with a bending stress of 60 pounds through 16 weeksafter adding another 10 pounds for a total of 70 pounds, according to anembodiment. No failure by the structure is indicated, suggesting thatthe tensile strength provided by the plastic frame suffices for asustained external load of at least 3×60=180 pounds per square foot anda temporary load of 3×70=210 pounds per square foot.

FIG. 10E is a photograph that depicts the example structure of FIG. 9Dexternally loaded with a bending stress of 70 pounds through 17 weeksafter adding another 11 pounds (an 8 pound barbell and a 3 pound disk)for a total of 81 pounds, according to an embodiment. No failure by thestructure is indicated, suggesting that the tensile strength provided bythe plastic frame suffices for a sustained external load of at least3×70=210 pounds per square foot and a temporary load of 3×81=243 poundsper square foot.

FIG. 10F is a photograph that depicts a side view of the examplestructure of FIG. 9D with 81 pounds at 17 weeks, according to anembodiment. A straight edge shows that there is very slight bending, asevident from the center of the structure being slightly closer to thestraight edge than the legs of the structure.

After additional weight was added, the structure failed. The forms andconcrete held 70 pounds securely with slight deformation. When the loadwas increased to 81 pounds, the form and concrete only held for a coupleof hours before it collapsed. Support at 70 pounds translates to a loadof 210 psf (10,054 n/m2); failure was at 81 pounds which translates to aload of 243 psf (11,635 n/m2).

Alternative, Enhancements and Modifications

In the foregoing specification, the invention has been described withreference to specific embodiments thereof. It will, however, be evidentthat various modifications and changes may be made thereto withoutdeparting from the broader spirit and scope of the invention. Thespecification and drawings are, accordingly, to be regarded in anillustrative rather than a restrictive sense. Throughout thisspecification and the claims, unless the context requires otherwise, theword “comprise” and its variations, such as “comprises” and“comprising,” will be understood to imply the inclusion of a stateditem, element or step or group of items, elements or steps but not theexclusion of any other item, element or step or group of items, elementsor steps. Furthermore, the indefinite article “a” or “an” is meant toindicate one or more of the item, element or step modified by thearticle.

What is claimed is:
 1. A building component system comprising: a rigidplastic form having an arched shape in each of two perpendicularvertical planes and having a plurality of protrusions configured toengage concrete poured on top of the rigid plastic form; and concretepoured on top of the form and cured to bind to the form at least at theplurality of protrusions, thereby forming an arched ceiling for a firststory of a building and a flat roof or flat floor for a second story ofa building, wherein the form is not removed and stays in place after theconcrete cures.
 2. The system of claim 1 wherein, when the form isplaced on a flat surface, a space below the form is sufficient for useas a residence for humans or animals or equipment or some combination.3. The system of claim 1 wherein the concrete is not reinforced withsteel.
 4. The system of claim 1 further comprising two or more temporaryvertical forms disposed outside the rigid plastic form for providing anouter perimeter of the building component, wherein the temporaryvertical forms are removed after the concrete is poured and cured. 5.The system of claim 1 wherein a plurality of the rigid plastic formsstack efficiently for transportation of the plurality of rigid plasticforms.
 6. The system of claim 1 further comprising a mold configured tofabricate the rigid plastic form by injection molding.
 7. The system ofclaim 1 wherein the arches are parabola shaped and designed to push theconcrete to pure compression.
 8. The system of claim 1 wherein thearches provide a great vertical extent so that the concrete is workingmore in compression and less reliant on the tensile strength of theform.
 9. A method comprising: placing a rigid plastic form having anarched shape in each of two perpendicular vertical planes and having aplurality of protrusions configured to engage concrete poured on top ofthe rigid plastic form; placing two or more simple vertical formsoutside the rigid plastic form for providing an outer perimeter of abuilding component; pouring and curing concrete on top of the form tobind to the form at least at the plurality of protrusions; and after theconcrete cures removing the two or more simple vertical forms, therebyforming an arched ceiling for a first story of a building and a flatroof or flat floor for a second story of a building.